Impact of mid-luteal phase GnRH agonist administration on reproductive outcomes in GnRH agonist-triggered cycles: A randomized controlled trial

Objective: To explore whether the addition of a mid-luteal bolus of GnRH agonist (GnRHa) improves the implantation rate (IR) in in vitro fertilization (IVF) cycles. Design: A randomized controlled trial. Setting: Private IVF center. Patients: 328 IVF/intracytoplasmic sperm injection patients were triggered with GnRHa and received 1,500 IU HCG on the day of oocyte pick-up (OPU) in addition to a standard luteal phase support (LPS). Intervention(s): In addition, the study group received a bolus of GnRHa 6 days after OPU, whereas the control group did not. Main outcome measure: Implantation rate. Secondary outcome measure(s): Ongoing pregnancy (OP) and live birth (LB) rates. Results: Although serum concentrations of FSH, LH, E2, and P on day OPU + 7 were significantly higher in the study group compared to the control group, the IR was not statistically different between the treatment group (27%) and the control group (23%) [odds ratio (OR) 1.2 (95% CI 0.9-1.7), P < 0.27]. Similarly, the OP rate was 37% in the treatment group and 31% in the control group [OR 1.3 (95% CI 0.8-2.0), P < 0.23]. The LB rate was 36% in the treatment group and 31% in the control group [OR: 1.3 (95% CI 0.8-2.0), P < 0.27]. Conclusion: Although a trend toward a higher IR and pregnancy rate was observed in the treatment group, this difference was not statistically significant. However, the absolute risk difference of 5% found for LB is clinically relevant, warranting further investigation.